The present invention is directed to a method and to devices for pressing a packing, a cover or a dressing against a cylinder. A roller can be deployed and retracted by an adjusting mechanism and can be covered by a guard.
EP 07 12 725 B1 discloses a device that is usable for pressing against printing plates with the aid of a number of rollers which are disposed along the cylinder circumference. In order to protect it from getting dirty, the device is disposed in a box-shaped dirt guard that can be moved out of the deployment region of the rollers. Additional opening flaps are disposed on the dirt guard and can be actuated by separate working cylinders.
EP 04 33 798 B1 has a pivotable guard for a changing device of a printing plate, which pivotable guard protects the entire apparatus, that is oriented toward the access side, from getting dirty. The pressing roller is a one piece roller, and working cylinders situated at both ends of the roller place it against the cylinder by use of a lever.
EP 07 10 556 B1 discloses a device for guiding the trailing end of a plate into a channel during plate installation. In this connection, after the leading end of the plate has been clamped in place, and after most of the plate has been mounted in place, a feeder carriage is moved against the cylinder and guides the trailing end of the plate into the channel by the use of an insertion slider disposed on the carriage.
The object of the present invention is to produce a method and devices for pressing a packing, a cover or a dressing against a cylinder blanket.
The object is attained according to the present invention by the use of at least one roller which is deployed and retracted by an adjusting mechanism. The roller can be covered, in the direction of the cylinder, by an actuating guard. Both the guard and the roller are actuated by the same adjusting mechanism. A stop on the device that deploys and retracts the at least one roller is engageable by the leading, acutely bent end of the packing, cover dressing or plate to be applied to the cylinder. The stop is inclined toward the cylinder. At one location, the spacing between the stop and the cylinder is less than the height of the acutely bent plate end.
The advantages that can be attained with the present invention are comprised particularly in that a guard is provided for the rollers. This guard limits the possibility of the rollers getting dirty when they are in the retracted position. The rollers and the guard are actuated with the same adjusting mechanism. The movements of both the guard and rollers can therefore occur synchronously and without incurring additional control and drive costs. It is particularly advantageous to couple the movable guards to the roller supports that are moved by the adjusting mechanism.
To accomplish an exact insertion of a leading end of a packing, cover or dressing into a channel in the cylinder, at least one stop is advantageously provided, which stop is stationary in relation to the machine frame. It is advantageous that when installing the packing, cover or dressing, the formation or structure of the stop imparts an initial stress on the leading end of the packing, cover or dressing, which permits the leading end to engage, in detent fashion, in the provided clamping or tensioning device in the cylinder in a manner that is reproducible because it is guided.